Motorola brings push-to-talk to Wi-Fi

The system, Cross-Technology Push-to-Talk over Cellular (CTPoC), is pitched at wireless carriers and is geared to allow PTT interoperability across GPRS and CDMA 2000 networks. That means applying CTPoC will allow carriers to support PTT roaming, Motorola says.

Operators will be able to allow other companies' customers to continue to use PTT when connected to their network, much as, say, a UK Orange customer can send text messages via Vodafone's Italian network.

However, a little-discussed aspect of the technology is Wi-Fi support. CTPoC is based on Motorola's IP-based IP Multimedia Sub-system (IMS), so technically any IP network can be used to be used as a transport for PTT communications.

CTPoC requires the use of client devices that can use the supported networks. So unless you have an 802.11-enabled PTT handset, don't expect to be able to get much joy out of your local hotspot. It probably won't work in any case unless the access point provides direct access to the Net - ie. you don't have to set up an access account first.

Motorola said CTPoC would also support W-CDMA/UTMS and WiMAX in the "future". Its development efforts are being overseen by the Open Mobile Alliance (OMA), it added. ®